Iannone was testing a new engine during his 40 laps and briefly dropped from the top spot – to rookie Johann Zarco – before going red in every sector to regain the fastest mark.

Aspar's Alvaro Bautista (2m00.218s) was third fastest, followed by Valentino Rossi and fastest rookie Zarco in wet conditions that postponed on-track action until the last hours of the session.

Aprilla rider Aleix Espargaro suffered a crash but managed to finish 11th fastest. Scott Redding (15th), Danilo Petrucci (17th), Loris Baz (18th) and Tito Rabat (23rd) also fell during the session. Rabat's fall at Turn 11 brought out a brief red flag with an hour to go; he was sent to a Putrajaya hospital, and MotoGP.com reports he suffered a fracture in his hand, wounds to his left knee, right food and both wrists. He will not take part in the final testing days.

Having opted against trying any new parts on the opening day, Yamaha debuted a new internal winglet during the session. Vinales was the only other rider to record a sub-two minute time, with Rossi not far behind in fourth (2m,00.254s).

Ducati riders Andrea Dovizioso dropped a bit from day one to seventh, followed by teammate Jorge Lorenzo, who improved on his P17 finish from the first day.

Riders will have a final day of testing before the second round of testing at Phillip Island.